Where possible, I use one of the practice quilting sandwiches to create a mini-sample. I record needle size, thread, tension and other info directly onto the fabric an ink pen. (Naturally won't work with heavy pattern!) Also, there are times when I have dipped one side of the sandwich in hot water and dried it then marked what section is and isn't washed. Then it gets popped into a plastic wallet and stored away. I like to see a physical reminder of what worked and definitely what didn't.